1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#include <sys/socket.h>
27#include <sys/stream.h>
28#include <sys/param.h>
29
30#include <net/route.h>
31#include <net/if.h>
32#include <netinet/in.h>
33#include <arpa/inet.h>
34
35#include <locale.h>
36
37#include <errno.h>
38#include <unistd.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <strings.h>
42#include <string.h>
43#include <stropts.h>
44#include <fcntl.h>
45#include <libdliptun.h>
46
47static void usage(void);
48
49static dladm_handle_t	handle;
50/* booleans corresponding to command line flags */
51static boolean_t	eflag = B_FALSE;
52static boolean_t	dflag = B_FALSE;
53static boolean_t	aflag = B_FALSE;
54
55
56/*
57 * printkstatus()
58 *
59 * Queries the kernel for the current 6to4 Relay Router value, prints
60 * a status message based on the value and exits this command.
61 * INADDR_ANY is used to denote that Relay Router communication support is
62 * disabled within the kernel.
63 */
64static void
65printkstatus(void)
66{
67	struct in_addr	rr_addr;
68	char		buf[INET6_ADDRSTRLEN];
69	char		errstr[DLADM_STRSIZE];
70	dladm_status_t	status;
71
72	status = dladm_iptun_get6to4relay(handle, &rr_addr);
73	if (status != DLADM_STATUS_OK) {
74		(void) fprintf(stderr, gettext("6to4relay: unable to get "
75		    "6to4 relay status: %s\n"),
76		    dladm_status2str(status, errstr));
77		return;
78	}
79	(void) printf("6to4relay: ");
80	if (rr_addr.s_addr == INADDR_ANY) {
81		(void) printf(gettext("6to4 Relay Router communication "
82		    "support is disabled.\n"));
83	} else {
84		(void) printf(gettext("6to4 Relay Router communication "
85		    "support is enabled.\n"));
86		(void) printf(gettext("IPv4 destination address of Relay "
87		    "Router = "));
88		(void) printf("%s\n",
89		    inet_ntop(AF_INET, &rr_addr, buf, sizeof (buf)));
90	}
91}
92
93/*
94 * modifyroute(cmd, in_gw)
95 *
96 * Modifies a default IPv6 route with DST = ::, GATEWAY = in_gw, NETMASK = ::
97 * and flags = <GATEWAY, STATIC>.
98 * This route is to be propagated through the 6to4 site so that 6to4 hosts
99 * can send packets to native IPv6 hosts behind a remote 6to4 Relay Router.
100 */
101static void
102modifyroute(unsigned int cmd, in6_addr_t *in_gw)
103{
104	static int rtmseq;
105	int rtsock;
106	int rlen;
107
108	static struct {
109		struct rt_msghdr	rt_hdr;
110		struct sockaddr_in6	rt_dst;
111		struct sockaddr_in6	rt_gate;
112		struct sockaddr_in6	rt_mask;
113	} rt_msg;
114
115	/* Open a routing socket for passing route commands */
116	if ((rtsock = socket(AF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
117		(void) fprintf(stderr, gettext("6to4relay: unable to modify "
118		    "default IPv6 route: socket: %s\n"), strerror(errno));
119		return;
120	}
121
122	(void) memset(&rt_msg, 0, sizeof (rt_msg));
123	rt_msg.rt_hdr.rtm_msglen = sizeof (rt_msg);
124	rt_msg.rt_hdr.rtm_version = RTM_VERSION;
125	rt_msg.rt_hdr.rtm_addrs = RTA_DST | RTA_GATEWAY | RTA_NETMASK;
126	rt_msg.rt_hdr.rtm_pid = getpid();
127	rt_msg.rt_hdr.rtm_type = cmd;
128	rt_msg.rt_hdr.rtm_seq = ++rtmseq;
129	rt_msg.rt_hdr.rtm_flags = RTF_STATIC | RTF_GATEWAY;
130
131	/* DST */
132	rt_msg.rt_dst.sin6_family = AF_INET6;
133	(void) memset(&rt_msg.rt_dst.sin6_addr.s6_addr, 0,
134	    sizeof (in6_addr_t));
135
136	/* GATEWAY */
137	rt_msg.rt_gate.sin6_family = AF_INET6;
138	bcopy(in_gw->s6_addr, &rt_msg.rt_gate.sin6_addr.s6_addr,
139	    sizeof (in6_addr_t));
140
141	/* NETMASK */
142	rt_msg.rt_mask.sin6_family = AF_INET6;
143	(void) memset(&rt_msg.rt_mask.sin6_addr.s6_addr, 0,
144	    sizeof (in6_addr_t));
145
146	/* Send the routing message */
147	rlen = write(rtsock, &rt_msg, rt_msg.rt_hdr.rtm_msglen);
148	if (rlen < rt_msg.rt_hdr.rtm_msglen) {
149		if (rlen < 0) {
150			(void) fprintf(stderr,
151			    gettext("6to4relay: write to routing socket: %s\n"),
152			    strerror(errno));
153		} else {
154			(void) fprintf(stderr, gettext("6to4relay: write to "
155			    "routing socket got only %d for rlen\n"), rlen);
156		}
157	}
158	(void) close(rtsock);
159}
160
161static void
162usage(void)
163{
164	(void) fprintf(stderr,
165	    gettext("usage:\n"
166	    "\t6to4relay\n"
167	    "\t6to4relay -e [-a <addr>]\n"
168	    "\t6to4relay -d\n"
169	    "\t6to4relay -h\n"));
170}
171
172int
173main(int argc, char **argv)
174{
175	int		ch;
176	char		*relay_arg = NULL;
177	dladm_status_t	status;
178	char		errstr[DLADM_STRSIZE];
179
180	(void) setlocale(LC_ALL, "");
181
182#if !defined(TEXT_DOMAIN)
183#define	TEXT_DOMAIN "SYS_TEST"
184#endif
185	(void) textdomain(TEXT_DOMAIN);
186
187	if ((status = dladm_open(&handle)) != DLADM_STATUS_OK) {
188		(void) fprintf(stderr, gettext("6to4relay: error opening "
189		    "dladm handle: %s\n"), dladm_status2str(status, errstr));
190		return (EXIT_FAILURE);
191	}
192
193	/* If no args are specified, print the current status. */
194	if (argc < 2) {
195		printkstatus();
196		return (EXIT_SUCCESS);
197	}
198
199	while ((ch = getopt(argc, argv, "ea:dh")) != EOF) {
200		switch (ch) {
201		case 'e':
202			eflag = B_TRUE;
203			break;
204		case 'd':
205			dflag = B_TRUE;
206			break;
207		case 'a':
208			aflag = B_TRUE;
209			relay_arg = optarg;
210			break;
211		case 'h':
212			usage();
213			return (EXIT_SUCCESS);
214		default:
215			usage();
216			return (EXIT_FAILURE);
217		}
218	}
219	/*
220	 * If -a is specified, -e must also be specified.  Also, the
221	 * combination of -e and -d is illegal.  Fail on either case.
222	 */
223	if ((aflag && !eflag) || (eflag && dflag)) {
224		usage();
225		return (EXIT_FAILURE);
226	}
227
228	/*
229	 * Enable Relay Router communication support in the kernel.
230	 */
231	if (eflag) {
232		struct in_addr current_addr;
233		struct in_addr new_addr;
234		in6_addr_t v6_rt;
235
236		/*
237		 * if -a was not specified, the well-known anycast will
238		 * be used.
239		 */
240		if (!aflag) {
241			new_addr.s_addr = htonl(INADDR_6TO4RRANYCAST);
242		} else if (inet_pton(AF_INET, relay_arg, &new_addr) <= 0) {
243			(void) fprintf(stderr, gettext("6to4relay: input "
244			    "address (%s) is not a valid IPv4 dotted-decimal "
245			    "string.\n"), relay_arg);
246			return (EXIT_FAILURE);
247		}
248
249		status = dladm_iptun_get6to4relay(handle, &current_addr);
250		if (status != DLADM_STATUS_OK) {
251			(void) fprintf(stderr, gettext("6to4relay: "
252			    "unable to obtain current 6to4 relay address: %s"),
253			    dladm_status2str(status, errstr));
254			return (EXIT_FAILURE);
255		}
256
257		if (current_addr.s_addr == new_addr.s_addr)
258			return (EXIT_SUCCESS);
259
260		status = dladm_iptun_set6to4relay(handle, &new_addr);
261		if (status != DLADM_STATUS_OK) {
262			(void) fprintf(stderr, gettext("6to4relay: "
263			    "unable to set the 6to4 relay router address: "
264			    "%s\n"), dladm_status2str(status, errstr));
265			return (EXIT_FAILURE);
266		}
267
268		if (current_addr.s_addr != INADDR_ANY) {
269			/* remove old default IPv6 route */
270			IN6_V4ADDR_TO_6TO4(&current_addr, &v6_rt);
271			modifyroute(RTM_DELETE, &v6_rt);
272		}
273
274		IN6_V4ADDR_TO_6TO4(&new_addr, &v6_rt);
275		modifyroute(RTM_ADD, &v6_rt);
276	}
277
278	/*
279	 * Disable Relay Router communication support in kernel.
280	 */
281	if (dflag) {
282		struct in_addr rr_addr;
283		in6_addr_t v6_rt;
284
285		/*
286		 * get Relay Router address from the kernel and delete
287		 * default IPv6 route that was added for it.
288		 */
289		status = dladm_iptun_get6to4relay(handle, &rr_addr);
290		if (status != DLADM_STATUS_OK) {
291			(void) fprintf(stderr, gettext("6to4relay: "
292			    "unable to obtain current 6to4 relay address: %s"),
293			    dladm_status2str(status, errstr));
294			return (EXIT_FAILURE);
295		}
296		if (rr_addr.s_addr == INADDR_ANY)
297			return (EXIT_SUCCESS);
298
299		IN6_V4ADDR_TO_6TO4(&rr_addr, &v6_rt);
300		modifyroute(RTM_DELETE, &v6_rt);
301
302		/*
303		 * INADDR_ANY (0.0.0.0) is used by the kernel to disable Relay
304		 * Router communication support.
305		 */
306		rr_addr.s_addr = INADDR_ANY;
307		status = dladm_iptun_set6to4relay(handle, &rr_addr);
308		if (status != DLADM_STATUS_OK) {
309			(void) fprintf(stderr, gettext("6to4relay: "
310			    "unable to disable tunneling to 6to4 relay router: "
311			    "%s\n"), dladm_status2str(status, errstr));
312			return (EXIT_FAILURE);
313		}
314	}
315
316	return (EXIT_SUCCESS);
317}
318